Alloys



Patented May 10, 1949 UNITED STATES TENT OFFICE Oberle, Mount Lebanon,

Pa., and Jerome Strauss, New York, N. Y., assignors to Vanadrum Corporation of America, New York, N. Y., a corporation of Delaware No Drawing. Application January 13, 1945, Serial No. 572,640

14 Claims.

This invention relates to alloys containing both beryllium and boron which alloys have among their properties an inherent resistance to softening at elevated temperatures. This property is of extreme importance when the alloys are used as nozzles for ejection of hot gases, parts for furnaces and other heat-generating and heat transfer devices, and as parts of engines and turbines which must retain high strength at elevated temperature for a considerable period of time. It also is of importance in cutting tools which may be required to operate at red heat. While the alloys are of particular importance for uses involving high strength at elevated temperature, they have a combination of physical properties including resistance to corrosion and oxidation which render them valuable for many industrial purposes at temperatures from below zero up to about 2000 F.

The alloys of our invention contain from to 40% chromium, preferably from 20 to 35% chromium. They contain one or more of tungsten, molybdenum, or uranium, these metals sometimes being referred to as tungsten-type" metals. Where the alloy contains tungsten alone or molybdenum alone or uranium alone, the tungsten-type metal is from 1 to 40%, the tungsten preferably being from to 30%, the molyb-.

denum from 2 to and the uranium from 2 to 20%. Where the alloy contains two of the tungsten-type metals, the preferred ranges of these metals in any combination are 3 to tungsten, 1 to 15% molybdenum and 2 to 15% uranium. Where the alloy contains three of the tungstentype metals, the preferred ranges of these metals are 3 to 15% tungsten, 1 to 10% molybdenum and 2 to 15% uranium. Molybdenum appears to be considerably more potent than tungsten. The addition of 3% molybdenum to chromiumnickel-cobalt-beryllium-boron base alloys gives the same hot hardness as the addition of about 11 to 13% tungsten. 6% molybdenum gives the 'same hot hardness as about 14 to 16% tungsten. 9% molybdenum gives the same hot hardness as about 16 to 18% tungsten. Uranium appears to have somewhat higher potency than tungsten. The ratio of molybdenum to tungsten in any replacement of tungsten by molybdenum varies from 1:6 to 1: 5, each per cent of molybdenum becoming less effective as a replacement for tungsten as the percentage of molybdenum increases. The alloys alsocontain one or more of the matrix metals cobalt, nickel or iron in total amount between 25% and 65% of the alloy. The total per cent of the matrix metals preferably is about 25 to 52% and much better results for many urposes are attained if this total per cent is not over about 44%.

In our alloys, beryllium is employed in amounts between 0.05 and 7%, preferably between 0.15 and 2%. The alloys contain 0.25 to 7% boron, preferably 0.50 to 2% boron. The carbon is generally between 0.01 and 3%, usually between 0.10 and 1% and preferably between 0.15 and .60%. For

-" '.alloys which are to be used in applications reou rmgmgh hardness at elevated temperatures, it is preferred to keep the carbon on the low side of the range and to obtain the required hardness by the use of beryllium and boron. For

5 other applications not requiring such high hard ness at elevated temperatures, the major hardening effect may be obtained from carbon so that the alloy is derived by employing carbon in the high side of the range together with beryllium and boron in the low side of these ranges. Where cutting qualities or abrasion resistance may be most important and high temperature strength less important, the alloy may contain carbon up to about 4 or 5 per cent.

Where the alloy contains tungsten as the only tungsten-type metal, a preferred composition range of our alloys is Per cent Chromium 20 to 35 Tungsten 10 to 35 Cobalt 20 to 28 Nickel 20 to 28 Beryllium 0.15 to 2 Boron 0.50 to 2 Carbon 0.10 to 1 Uranium may be substituted for part or all of the tungsten in somewhat lower percentages than tungsten. Molybdenum may be substituted for I part or allof the tungsten, but due to the greater potency of molybdenum as previously pointed out, the amount of molybdenum required ot give the same hot hardness is less than would be required for tungsten.

It has been observed that elements of small atomic diameter exert a powerful influence as hardeners in some alloys. Since it is possible for elements of small atomic diameter to occupy the interstices between atoms of much larger atomic diameter, carbon (atomic diameter 1.5 21.), boron (atomic diameter 1.9 A.) and beryllium (2.25 A.) may form interstitial solid solutions with chromium (2.71 A), tungsten (2.82 A), molybdenum (2.80 A.), uranium (2.83 .41.), iron (2.52 A. cobalt (2.50 A.) and nickel (2.49 A). Also possible is Table- 2 .-3 i. gm, I fi VW Mo .11 ,Cr Ni Co Fe Bo B 11; 32.55; 23; j 0. 50 0.90 12 18 4.50 3.. O. 55 19 25 05 75 4. 0.30 .3' 2. 50 5 0.75 .40 1. 50 6 L804." 1- 40' 14' 6.25 7 O. 60 6- f 2. 50 8... 0. l5 1 4 30 26 0.80 9 0. 22 39 0. 50 10 1. 00 1 Q2 25 "25' 0.75 11.. 0. 65 4 29 1. 50 121. -1.-00- 1-1 20' 0.65 13:. "0235' 15 27 1 14" 0. 10 12 6 .1" 27 20 41.00 15 0.5 0 19 v 7 32 22 1.75, 16 3100' ;-25 3 I 20 1'26 0.55 17.. 1. 25 22 O. 70 1s 0. 5o 20 1 19 0,90 20 2. 00 m 0.- 40 -22" "0. 50 2 .05 .24. 1'. 75 '22 0150 1.25

" In our alloys in addition tochromium, the

"tun sten-type -r-neta-ls, the matrix metals, beryliiuihand boron, there maybe present small amounts of other elements such as silicon,"

manganese, aluminum, magnesium, calcium, barium, strontium, titanium, zirconium, vanadium, etc., depending upon (1) the purity of the metals and alloys used in making the heats, (2) the method of melting and the refractories used, and l (3) deoxidation and degasifying practices, or (4) small percentages intentionally added to improve casting or fabricating properties, to control ascast grain size or to contribute to strength, toughness, etc. The amount of each such element should be restricted to percentages which do not adversely affect the desired properties of the alloy; in many cases the additional element will not exceed about 1%.

As used herein, the term tungsten-type metal" is intended to include tungsten, molybdenum or uranium or any combination thereof. This term does not include chromium.

The method of forming the alloys into shape may be varied somewhat depending upon the specific composition selected and the intended use of the article. Both sand molds and cast iron or other permanent or semi-permanent molds are satisfactory for casting ingots and other forms which may be rolled, machined or ground into final shape. Centrifugal or pressure casting is preferred for thin or complex sections. For parts to be forged into shape, the alloys toward the low side in tungsten, cobalt and beryllium are preferred. While the alloys may be used in the cast condition, they are also responsive to heat treatment. A solution heat treatment consisting of heating any of these alloys to a temperature somewhat below its softening range followed by rapid cooling, for example, cooling in water, oil or air, results in a more homogenous alloy with uniform structure as revealed by micro-examination. Subsequent aging at temperatures from 1000 F. to 1800 F. for fifteen minutes to 24 hours produces stabilized alloys of extremely uniform hardness.

The invention is not limited to the preferred embodiments which have been given merely for purposes of illustration but may be otherwise embodied within the scope of the following claims.

We claim:

1. An alloy consisting essentially of 5 to 40% chromium, 1 to 40% of at least one tungstentype metal of the group consisting of tungsten, molybdenum and uranium, 0.05 to 7% beryllium (me re 7 %1' boron3- 00rto 3'7f carbtnaameitcti amount of cobal anti an efiective a-mcunter nickel,thesiim of the -cobalt andinickel consti= tuting 25 to 65% of the alloy, the: ilungstemtype metalsi; exceeding 40%oii'the alley.

' 2. An' alloy 'consistingi essentially 'of Etc 40% chromium ILt'O 40%"ofl aii'least one tungsten-type metal or tli'e group consisting.olitungstemmolybden-um and: urianium',- 0.05 to "7% beryllium, 0125 to 7 boron, ot-0am 3% carbom at least 15% cobalt and atleash -15 nickel, the sum of if the cobalt and nickel: constituting'i30-to52% =-or the alloy;

3.1 mi alloy-containingfi mica; chromium,f1 to 40 %r ofi"atleasif one tungsten-t'ypermetal of the group consisting Ofii tungsten, molybdenumi-and 111 311111111; 0.05" to '7 beryllium, 0125 to 7 boron, 0.01 to 3% carbons-not over about 5% iron, the balance being substantially '-all"- nickel and cobalt, the nickel comprising;from;15 to 39'%- of the-alloy, the cobalt: com-prlsingg from w to 40% of the "alloy; the sum of the-nickel; cobalt and: iron. being not'o'ver 65%: oi -"the alloy,'the tungsten type metals not exceeding 40% of the alloy.

ii-An "alloy containing, '5'=to =40 chromium, 1 to 40% of at least one tungsten-type metal of the group consisting of tungsten, molybdenum and uranium, 0.05 to 7% beryllium, 0.25 to 7% boron, 0.01 to 3% carbon, not over about 5% iron, the balance being substantially all nickel and cobalt, the nickel constituting at least 15% of the alloy, the cobalt constituting at least 15% of the alloy, the sum of the nickel, cobalt and iron being not over 52% of the alloy, the tungstentype metals not exceedin 40% of the alloy.

5. An alloy containing 5 to 40% chromium, 1 to 40% of at least one tungsten-type metal of the group consisting of tungsten, molybdenum and uranium, 0.05 to 7% beryllium, 0.25 to 7% boron, 0.01 to 3% carbon, not over about 5% iron, the balance being substantially all nickel and cobalt, the nickel constituting at least 15% of the alloy, the cobalt constituting at least 15% of the alloy, the sum of the nickel, cobalt and "iron being not over 44% of the alloy, the tungstentype metals not exceeding 40% of the alloy.

6. An alloy containing 5 to 40% chromium, 1 to 40% tungsten, 0.05 to 7% beryllium, 0.25 to 7% boron, 0.01 to 3% carbon, not over about 5% iron, the balance being substantially all nickel and cobalt, the nickel comprising from 15 to 39% of the alloy, the cobalt comprising from 15 to 40% of the alloy, the sum of the nickel, cobalt and iron being not over 65% of the alloy.

7. An alloy consisting essentially of 20 to 35% chromium, 10 to 35% tungsten, 20 to 28% cobalt, 20 to 28% nickel, 0.15 to 2% beryllium, 0.50 to 2% boron, and 0.10 to 1% carbon.

8. An alloy consisting essentially of 5 to 40% chromium, 1 to 40% of at least one tungstentype metal of the group consisting of tungsten, molybdenum and uranium, 0.05 to 7% beryllium, 0.25 to 7% boron, 0.01 to 3% carbon, an effective amount of cobalt and an eifective amount of nickel, the sum of the cobalt and nickel constituting 25 to 52% of the alloy, the tungsten-type metals not exceeding 40% of the alloy.

9. An alloy consisting essentially of 5 to 40% chromium, 1 to 40% molybdenum, 0.05 to 7% beryllium, 0.25 to 7% boron, 0.01 to 3% carbon, an effective amount of cobalt and an effective amount of nickel, the sum of the cobalt and nickel constituting 25 to 65% of the alloy.

10. An alloy consisting essentially of 5 to 40% chromium, 1 to 40% molybdenum, 0.05 to 7% ,s2% orthe 11oy. I ,11. An alloymontainingfi' to 40% chromium,-

, 7' I berymum; 0.254017% borgn; 0.01 to 3 carbon,

at least -15 cobaltj and at least 15% nickel, the I I I I sum of the cobalt and nickel constituting I 30 to j I j ,1 t-40j% mo1ybdenum..0.05 to 7%Ibery11ium; 0.25; e 007% boron; 0.01 203% carbon, not over about %irengthe balamebeing substantially an nidkel I and cobalt, the nickel comprising. from 15 to 39% 10 or the alloy the sum ofthe nickeLcobaLt and 7 iron being not over 65% of the alloy.

of the alloy; the cobaltcomprising from to 12; An alloycorisi'sting essentiallyof 5 to 40% the alloy.

14.'An' alloycontainingfi to 40% chromium,

bQing'nOt over 0f the alloy;

1 to. 40% uranium, 0.05- 7.%--ber.y,11ium, 0.25 t6 y "7% boron,0.01 to, 3% carbon, not over about 5% i iron; the balance being I substantially all nickel I andcobaln-the nickel comprising from 15 to 39% of the alloy, the c balt comprising from 15 to 40% I Iof the alloy, the s um'of the'nickel cobalt and. iron,

DANIEL LEONARD EDLUND; I

' THEODORE LORING OBERLE. e I

' JEROME STRAUSS.

REFERENCES crmn I The followingref'erences' are ofrecord inthe I I file of: this patent:

UNITED STATES PATENTS Wissler Mar; 4, 1941 

